<?php
/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 2018/5/23
 * Time: 16:09
 */

namespace app\api\service;


use app\lib\enum\ScopeEnum;
use app\lib\exception\TokenException;
use app\lib\exception\WhChatException;
use app\api\Model\User as UserModel;
use think\Exception;

class UserToken extends Token
{
    protected $code;
    protected $wxAppID;
    protected $wxAppSecret;
    protected $wxLoginUrl;

    function __construct($code)
    {
        $this->code = $code;
        $this->wxAppID = config('wx.app_id');
        $this->wxAppSecret = config('wx.app_secret');
        $this->wxLoginUrl = sprintf(config('wx.login_url'),
            $this->wxAppID, $this->wxAppID, $this->code);
    }

    public function get($code)
    {
        $result = curl_get($this->wxLoginUrl);
        //后面是true变为数组
        $wxResult = json_encode($result, true);
        if (empty($wxResult)) {
            throw new Exception('获取session_key及openID时异常，微信内部错误');
        } else {
            $loginFail = array_key_exists('errcode', $wxResult);
            if ($loginFail) {
                $this->processLoginError($wxResult);
            } else {
               return $this->grantToken($wxResult);
            }
        }
    }

    private function grantToken($wxResult)
    {
        //拿到openID
        //数据库里看一下，这个openID是否存在
        //如果存在则不处理，如果不存在新增一条user记录
        //生成令牌，准备缓存数据，写入缓存
        //把令牌返回客户端
        //key:令牌
        //value:wx_result uid
        $openid = $wxResult['openid'];
        $user = UserModel::getByOpenID($openid);
        if ($user) {
            $uid = $user->id;
        } else {
            $uid = $this->newUser($openid);
        }
        $cachedValue = $this->prepareCachedValue($wxResult,$uid);
        $token =$this->saveToCache($cachedValue);
    }

    private function saveToCache($cachedValue){
       $key = self::generateToken();
       $value = json_encode($cachedValue);
       $expire_in = config('setting.token_expire_in');
        $request = cache($key,$value,$expire_in);
        if(!$request){
            throw new TokenException([
               'msg'=>'服务器异常',
                'errorCode' => 10005,
            ]);
        }
        return $key;
    }

    private function prepareCachedValue($wxResult,$uid){
        $cachedValue = $wxResult;
        $cachedValue['uid'] = $uid;
        //16 代表APP用户的权限数值
        $cachedValue['scope'] = ScopeEnum::User;

        //32 代表CMS(管理员) 用户的权限
//        $cachedValue['scope'] = ScopeEnum::Super;
        return $cachedValue;

    }
    private function newUser($openid)
    {
        $user = UserModel::create([
            'openid' => $openid
        ]);
        return $user->id;
    }

    private function processLoginError($wxResult)
    {
        throw new WhChatException([
            'msg' => $wxResult['errmsg'],
            'errorCode' => $wxResult['errcode']
        ]);
    }

}